If you don't have some kind of professional binding apparatus (or a stapler), you're in luck. Redditor blacksharpie figured out a clever binding trick that involves a rubber band and a paper clip.

The method is pretty simple to understand by just looking at the image above. You make two holes in the pages (if they aren't already there), loop a rubber band through the holes from the back of the pages, and attach each end of the band to each end of a paper clip. When you're done, the pages are bound—and it looks pretty nice, too!